This invention relates generally to electrical hazard prevention, and more specifically to a shock hazard prevention system for disconnecting an electrical load from an electrical source when a shock hazard condition exists within the load.
Devices for protecting human life and property against electrical shock and damage resulting from a shock hazard condition within an electrical load are known. For example, the model No. 6199 ground fault circuit interruptor (GFCI) marketed by the assignee of the present invention is capable of sensing and responding to the inadvertent grounding of the neutral conductor of an A-C electrical distribution system. It is noted, however, that in certain applications the utilization of such a GFCI is not practical.
In particular, the GFCI is a relatively expensive and complex device which requires the utilization of several transformers. In addition, the GFCI is often hardwired in a wall outlet or receptacle and is neither portable nor readily disconnected. Thus, unless each outlet in which an electrical device such as, for example, an appliance is to be utilized is protected by a GFCI, the user of the appliance is subject to possible injury if a shock hazard condition should exist in conjunction with a non-protected outlet.
In addition, in certain environments the utilization of a conventional GFCI would not afford any shock hazard protection to the user of an appliance. More specifically, a conventional GFCI device of the type known to applicants will not be effective or work if the user of an electrical appliance drops the appliance in a plastic insulated bathtub.
Another potential drawback, exists regarding the use of a GFCI for certain types of portable electrical appliances such as, for example, a hair dryer. Although the owner of a hair dryer may have his or her residence outlets adequately protected by GFCI devices, it is possible that other places, such as hotels, the residences of relatives, friends, etc., where it is desired to use the hair dryer, may not be protected by such devices.